"synchronize a file's in-core state with that on disk"
#include <unistd.h> intfsync(int fd);
causes all modified data and attributes of
to be moved to a permanent storage device.
This normally results in all in-core modified copies
of buffers for the associated file to be written to a disk.
should be used by programs that require a file to be in a known state,
for example, in building a simple transaction facility.
A 0 value is returned on success.
A \-1 value indicates an error.
is not a valid descriptor.
refers to a socket, not to a file.
An I/O error occurred while reading from or writing to the file system.